Strongyloides stercoralis colitis in a patient positive for human T-cell leukaemia virus with rheumatoid arthritis during an anti-rheumatic therapy: a case report

Abstract

An elderly woman with rheumatoid arthritis (RA) presented with a chief complaint of abdominal pain and diarrhoea while undergoing treatment with low-dose corticosteroids and abatacept. Endoscopic and histopathological findings revealed manifestations of ulcerative colitis (UC). An intermediate dose of corticosteroids and 5-aminosalicylic acid were administered. Abatacept was discontinued; the anti-TNF biologic, golimumab, was administered for treatment of both RA and UC. However, colitis worsened in response to this therapeutic regimen. Colonoscopy revealed severe mucosal lesions; larvae were detected in samples taken from multiple shallow mucosal ulcers. The patient was diagnosed with Strongyloides stercoralis colitis based on the results of an anti-parasite antibody test and examination of the larval DNA. Furthermore, serology revealed a positive test for antibodies against human T-cell leukaemia virus type 1 (HTLV-1). Immunosuppressive treatment was terminated; ivermectin was administered, which resulted in improvements in colitis symptoms within a few weeks. There are several published reports describing S. stercoralis colitis as a lethal mimic of UC. Corticosteroid and anti-TNF therapies have been reported as among the major risk factors associated with strongyloidiasis in patients with HTLV-1 infection. Therefore, HTLV-1 and Strongyloides infections may be considered in cases of new-onset gastrointestinal symptoms during immunosuppressive therapy, particularly in HTLV-1-endemic regions.

Keywords:

• Strongyloidiasis
• parasite infection
• human T-cell leukaemia virus type 1
• rheumatoid arthritis
• biologics

Acknowledgments

The authors thank Professor Yujiro Asada of the University of Miyazaki, Pathophysiology Section, Department of Pathology, for help in preparation of both figures and legends of pathological findings of mucosal lesion. He contributed revision of manuscript and important intellectual content as pathologist. We would like to thank Enago (https://www.enago.jp/) for English language editing.

Patient consent

Written informed consent for the publication of this report was obtained from the patient.

Conflict of interest

None.

Author contributions

YH and KU are the principal investigators of this case who drafted the manuscript. HM, AK, YH, and KU performed clinical assessment and data collection. EN and HM performed parasite antibody test and DNA examination. TH and AO provided support in drafting the manuscript. YH and KU submitted this manuscript.

Additional information

Funding

This report did not receive any funding support from public or private organizations.